Bentho-pelagic relations in the deep-water part of the Okhotsk Sea by the data of stable isotopes and N analysis

Composition, abundance, diet and trophic status are analyzed for dominant benthic and pelagic species in the deep-water Okhotsk Sea on the data collected in demersal and pelagic trawl surveys conducted by Pacific Fisheries Research Center (TINRO). Isotope composition is determined for tissues of 107 species of plankton, benthos, demersal fish, and cephalopods, which form a basis of pelagic and benthic communities. 30 % of examined species of demersal fishes and cephalopods use resources of detritus food chain as the base of their diet. Trophic relations in the deep-water Okhotsk Sea demonstrates high dependence between benthic and pelagic communities, as far as many dominant species of pelagic and demersal nekton consume both benthic and pelagic food. Feeding about of 70 % of dominant species of demersal fishes and cephalopods is based on grazing rather than on detritus food.